diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
new file mode 100644
index 0000000..b6b8a41
--- /dev/null
+++ b/drivers/kvm/kvm_main.c
@@ -0,0 +1,1935 @@
+/*
+ * Kernel-based Virtual Machine driver for Linux
+ *
+ * This module enables machines with Intel VT-x extensions to run virtual
+ * machines without emulation or binary translation.
+ *
+ * Copyright (C) 2006 Qumranet, Inc.
+ *
+ * Authors:
+ *   Avi Kivity   <avi@qumranet.com>
+ *   Yaniv Kamay  <yaniv@qumranet.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "kvm.h"
+
+#include <linux/kvm.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <asm/processor.h>
+#include <linux/percpu.h>
+#include <linux/gfp.h>
+#include <asm/msr.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/vmalloc.h>
+#include <asm/uaccess.h>
+#include <linux/reboot.h>
+#include <asm/io.h>
+#include <linux/debugfs.h>
+#include <linux/highmem.h>
+#include <linux/file.h>
+#include <asm/desc.h>
+
+#include "x86_emulate.h"
+#include "segment_descriptor.h"
+
+MODULE_AUTHOR("Qumranet");
+MODULE_LICENSE("GPL");
+
+struct kvm_arch_ops *kvm_arch_ops;
+struct kvm_stat kvm_stat;
+EXPORT_SYMBOL_GPL(kvm_stat);
+
+static struct kvm_stats_debugfs_item {
+	const char *name;
+	u32 *data;
+	struct dentry *dentry;
+} debugfs_entries[] = {
+	{ "pf_fixed", &kvm_stat.pf_fixed },
+	{ "pf_guest", &kvm_stat.pf_guest },
+	{ "tlb_flush", &kvm_stat.tlb_flush },
+	{ "invlpg", &kvm_stat.invlpg },
+	{ "exits", &kvm_stat.exits },
+	{ "io_exits", &kvm_stat.io_exits },
+	{ "mmio_exits", &kvm_stat.mmio_exits },
+	{ "signal_exits", &kvm_stat.signal_exits },
+	{ "irq_exits", &kvm_stat.irq_exits },
+	{ 0, 0 }
+};
+
+static struct dentry *debugfs_dir;
+
+#define MAX_IO_MSRS 256
+
+#define CR0_RESEVED_BITS 0xffffffff1ffaffc0ULL
+#define LMSW_GUEST_MASK 0x0eULL
+#define CR4_RESEVED_BITS (~((1ULL << 11) - 1))
+#define CR8_RESEVED_BITS (~0x0fULL)
+#define EFER_RESERVED_BITS 0xfffffffffffff2fe
+
+struct vmx_msr_entry *find_msr_entry(struct kvm_vcpu *vcpu, u32 msr)
+{
+	int i;
+
+	for (i = 0; i < vcpu->nmsrs; ++i)
+		if (vcpu->guest_msrs[i].index == msr)
+			return &vcpu->guest_msrs[i];
+	return 0;
+}
+EXPORT_SYMBOL_GPL(find_msr_entry);
+
+#ifdef __x86_64__
+// LDT or TSS descriptor in the GDT. 16 bytes.
+struct segment_descriptor_64 {
+	struct segment_descriptor s;
+	u32 base_higher;
+	u32 pad_zero;
+};
+
+#endif
+
+unsigned long segment_base(u16 selector)
+{
+	struct descriptor_table gdt;
+	struct segment_descriptor *d;
+	unsigned long table_base;
+	typedef unsigned long ul;
+	unsigned long v;
+
+	if (selector == 0)
+		return 0;
+
+	asm ("sgdt %0" : "=m"(gdt));
+	table_base = gdt.base;
+
+	if (selector & 4) {           /* from ldt */
+		u16 ldt_selector;
+
+		asm ("sldt %0" : "=g"(ldt_selector));
+		table_base = segment_base(ldt_selector);
+	}
+	d = (struct segment_descriptor *)(table_base + (selector & ~7));
+	v = d->base_low | ((ul)d->base_mid << 16) | ((ul)d->base_high << 24);
+#ifdef __x86_64__
+	if (d->system == 0
+	    && (d->type == 2 || d->type == 9 || d->type == 11))
+		v |= ((ul)((struct segment_descriptor_64 *)d)->base_higher) << 32;
+#endif
+	return v;
+}
+EXPORT_SYMBOL_GPL(segment_base);
+
+int kvm_read_guest(struct kvm_vcpu *vcpu,
+			     gva_t addr,
+			     unsigned long size,
+			     void *dest)
+{
+	unsigned char *host_buf = dest;
+	unsigned long req_size = size;
+
+	while (size) {
+		hpa_t paddr;
+		unsigned now;
+		unsigned offset;
+		hva_t guest_buf;
+
+		paddr = gva_to_hpa(vcpu, addr);
+
+		if (is_error_hpa(paddr))
+			break;
+
+		guest_buf = (hva_t)kmap_atomic(
+					pfn_to_page(paddr >> PAGE_SHIFT),
+					KM_USER0);
+		offset = addr & ~PAGE_MASK;
+		guest_buf |= offset;
+		now = min(size, PAGE_SIZE - offset);
+		memcpy(host_buf, (void*)guest_buf, now);
+		host_buf += now;
+		addr += now;
+		size -= now;
+		kunmap_atomic((void *)(guest_buf & PAGE_MASK), KM_USER0);
+	}
+	return req_size - size;
+}
+EXPORT_SYMBOL_GPL(kvm_read_guest);
+
+int kvm_write_guest(struct kvm_vcpu *vcpu,
+			     gva_t addr,
+			     unsigned long size,
+			     void *data)
+{
+	unsigned char *host_buf = data;
+	unsigned long req_size = size;
+
+	while (size) {
+		hpa_t paddr;
+		unsigned now;
+		unsigned offset;
+		hva_t guest_buf;
+
+		paddr = gva_to_hpa(vcpu, addr);
+
+		if (is_error_hpa(paddr))
+			break;
+
+		guest_buf = (hva_t)kmap_atomic(
+				pfn_to_page(paddr >> PAGE_SHIFT), KM_USER0);
+		offset = addr & ~PAGE_MASK;
+		guest_buf |= offset;
+		now = min(size, PAGE_SIZE - offset);
+		memcpy((void*)guest_buf, host_buf, now);
+		host_buf += now;
+		addr += now;
+		size -= now;
+		kunmap_atomic((void *)(guest_buf & PAGE_MASK), KM_USER0);
+	}
+	return req_size - size;
+}
+EXPORT_SYMBOL_GPL(kvm_write_guest);
+
+static int vcpu_slot(struct kvm_vcpu *vcpu)
+{
+	return vcpu - vcpu->kvm->vcpus;
+}
+
+/*
+ * Switches to specified vcpu, until a matching vcpu_put()
+ */
+static struct kvm_vcpu *vcpu_load(struct kvm *kvm, int vcpu_slot)
+{
+	struct kvm_vcpu *vcpu = &kvm->vcpus[vcpu_slot];
+
+	mutex_lock(&vcpu->mutex);
+	if (unlikely(!vcpu->vmcs)) {
+		mutex_unlock(&vcpu->mutex);
+		return 0;
+	}
+	return kvm_arch_ops->vcpu_load(vcpu);
+}
+
+static void vcpu_put(struct kvm_vcpu *vcpu)
+{
+	kvm_arch_ops->vcpu_put(vcpu);
+	put_cpu();
+	mutex_unlock(&vcpu->mutex);
+}
+
+static int kvm_dev_open(struct inode *inode, struct file *filp)
+{
+	struct kvm *kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
+	int i;
+
+	if (!kvm)
+		return -ENOMEM;
+
+	spin_lock_init(&kvm->lock);
+	INIT_LIST_HEAD(&kvm->active_mmu_pages);
+	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+		struct kvm_vcpu *vcpu = &kvm->vcpus[i];
+
+		mutex_init(&vcpu->mutex);
+		vcpu->mmu.root_hpa = INVALID_PAGE;
+		INIT_LIST_HEAD(&vcpu->free_pages);
+	}
+	filp->private_data = kvm;
+	return 0;
+}
+
+/*
+ * Free any memory in @free but not in @dont.
+ */
+static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
+				  struct kvm_memory_slot *dont)
+{
+	int i;
+
+	if (!dont || free->phys_mem != dont->phys_mem)
+		if (free->phys_mem) {
+			for (i = 0; i < free->npages; ++i)
+				__free_page(free->phys_mem[i]);
+			vfree(free->phys_mem);
+		}
+
+	if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
+		vfree(free->dirty_bitmap);
+
+	free->phys_mem = 0;
+	free->npages = 0;
+	free->dirty_bitmap = 0;
+}
+
+static void kvm_free_physmem(struct kvm *kvm)
+{
+	int i;
+
+	for (i = 0; i < kvm->nmemslots; ++i)
+		kvm_free_physmem_slot(&kvm->memslots[i], 0);
+}
+
+static void kvm_free_vcpu(struct kvm_vcpu *vcpu)
+{
+	kvm_arch_ops->vcpu_free(vcpu);
+	kvm_mmu_destroy(vcpu);
+}
+
+static void kvm_free_vcpus(struct kvm *kvm)
+{
+	unsigned int i;
+
+	for (i = 0; i < KVM_MAX_VCPUS; ++i)
+		kvm_free_vcpu(&kvm->vcpus[i]);
+}
+
+static int kvm_dev_release(struct inode *inode, struct file *filp)
+{
+	struct kvm *kvm = filp->private_data;
+
+	kvm_free_vcpus(kvm);
+	kvm_free_physmem(kvm);
+	kfree(kvm);
+	return 0;
+}
+
+static void inject_gp(struct kvm_vcpu *vcpu)
+{
+	kvm_arch_ops->inject_gp(vcpu, 0);
+}
+
+static int pdptrs_have_reserved_bits_set(struct kvm_vcpu *vcpu,
+					 unsigned long cr3)
+{
+	gfn_t pdpt_gfn = cr3 >> PAGE_SHIFT;
+	unsigned offset = (cr3 & (PAGE_SIZE-1)) >> 5;
+	int i;
+	u64 pdpte;
+	u64 *pdpt;
+	struct kvm_memory_slot *memslot;
+
+	spin_lock(&vcpu->kvm->lock);
+	memslot = gfn_to_memslot(vcpu->kvm, pdpt_gfn);
+	/* FIXME: !memslot - emulate? 0xff? */
+	pdpt = kmap_atomic(gfn_to_page(memslot, pdpt_gfn), KM_USER0);
+
+	for (i = 0; i < 4; ++i) {
+		pdpte = pdpt[offset + i];
+		if ((pdpte & 1) && (pdpte & 0xfffffff0000001e6ull))
+			break;
+	}
+
+	kunmap_atomic(pdpt, KM_USER0);
+	spin_unlock(&vcpu->kvm->lock);
+
+	return i != 4;
+}
+
+void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
+{
+	if (cr0 & CR0_RESEVED_BITS) {
+		printk(KERN_DEBUG "set_cr0: 0x%lx #GP, reserved bits 0x%lx\n",
+		       cr0, vcpu->cr0);
+		inject_gp(vcpu);
+		return;
+	}
+
+	if ((cr0 & CR0_NW_MASK) && !(cr0 & CR0_CD_MASK)) {
+		printk(KERN_DEBUG "set_cr0: #GP, CD == 0 && NW == 1\n");
+		inject_gp(vcpu);
+		return;
+	}
+
+	if ((cr0 & CR0_PG_MASK) && !(cr0 & CR0_PE_MASK)) {
+		printk(KERN_DEBUG "set_cr0: #GP, set PG flag "
+		       "and a clear PE flag\n");
+		inject_gp(vcpu);
+		return;
+	}
+
+	if (!is_paging(vcpu) && (cr0 & CR0_PG_MASK)) {
+#ifdef __x86_64__
+		if ((vcpu->shadow_efer & EFER_LME)) {
+			int cs_db, cs_l;
+
+			if (!is_pae(vcpu)) {
+				printk(KERN_DEBUG "set_cr0: #GP, start paging "
+				       "in long mode while PAE is disabled\n");
+				inject_gp(vcpu);
+				return;
+			}
+			kvm_arch_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
+			if (cs_l) {
+				printk(KERN_DEBUG "set_cr0: #GP, start paging "
+				       "in long mode while CS.L == 1\n");
+				inject_gp(vcpu);
+				return;
+
+			}
+		} else
+#endif
+		if (is_pae(vcpu) &&
+			    pdptrs_have_reserved_bits_set(vcpu, vcpu->cr3)) {
+			printk(KERN_DEBUG "set_cr0: #GP, pdptrs "
+			       "reserved bits\n");
+			inject_gp(vcpu);
+			return;
+		}
+
+	}
+
+	kvm_arch_ops->set_cr0(vcpu, cr0);
+	vcpu->cr0 = cr0;
+
+	spin_lock(&vcpu->kvm->lock);
+	kvm_mmu_reset_context(vcpu);
+	spin_unlock(&vcpu->kvm->lock);
+	return;
+}
+EXPORT_SYMBOL_GPL(set_cr0);
+
+void lmsw(struct kvm_vcpu *vcpu, unsigned long msw)
+{
+	set_cr0(vcpu, (vcpu->cr0 & ~0x0ful) | (msw & 0x0f));
+}
+EXPORT_SYMBOL_GPL(lmsw);
+
+void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
+{
+	if (cr4 & CR4_RESEVED_BITS) {
+		printk(KERN_DEBUG "set_cr4: #GP, reserved bits\n");
+		inject_gp(vcpu);
+		return;
+	}
+
+	if (kvm_arch_ops->is_long_mode(vcpu)) {
+		if (!(cr4 & CR4_PAE_MASK)) {
+			printk(KERN_DEBUG "set_cr4: #GP, clearing PAE while "
+			       "in long mode\n");
+			inject_gp(vcpu);
+			return;
+		}
+	} else if (is_paging(vcpu) && !is_pae(vcpu) && (cr4 & CR4_PAE_MASK)
+		   && pdptrs_have_reserved_bits_set(vcpu, vcpu->cr3)) {
+		printk(KERN_DEBUG "set_cr4: #GP, pdptrs reserved bits\n");
+		inject_gp(vcpu);
+	}
+
+	if (cr4 & CR4_VMXE_MASK) {
+		printk(KERN_DEBUG "set_cr4: #GP, setting VMXE\n");
+		inject_gp(vcpu);
+		return;
+	}
+	kvm_arch_ops->set_cr4(vcpu, cr4);
+	spin_lock(&vcpu->kvm->lock);
+	kvm_mmu_reset_context(vcpu);
+	spin_unlock(&vcpu->kvm->lock);
+}
+EXPORT_SYMBOL_GPL(set_cr4);
+
+void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
+{
+	if (kvm_arch_ops->is_long_mode(vcpu)) {
+		if ( cr3 & CR3_L_MODE_RESEVED_BITS) {
+			printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n");
+			inject_gp(vcpu);
+			return;
+		}
+	} else {
+		if (cr3 & CR3_RESEVED_BITS) {
+			printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n");
+			inject_gp(vcpu);
+			return;
+		}
+		if (is_paging(vcpu) && is_pae(vcpu) &&
+		    pdptrs_have_reserved_bits_set(vcpu, cr3)) {
+			printk(KERN_DEBUG "set_cr3: #GP, pdptrs "
+			       "reserved bits\n");
+			inject_gp(vcpu);
+			return;
+		}
+	}
+
+	vcpu->cr3 = cr3;
+	spin_lock(&vcpu->kvm->lock);
+	vcpu->mmu.new_cr3(vcpu);
+	spin_unlock(&vcpu->kvm->lock);
+}
+EXPORT_SYMBOL_GPL(set_cr3);
+
+void set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8)
+{
+	if ( cr8 & CR8_RESEVED_BITS) {
+		printk(KERN_DEBUG "set_cr8: #GP, reserved bits 0x%lx\n", cr8);
+		inject_gp(vcpu);
+		return;
+	}
+	vcpu->cr8 = cr8;
+}
+EXPORT_SYMBOL_GPL(set_cr8);
+
+void fx_init(struct kvm_vcpu *vcpu)
+{
+	struct __attribute__ ((__packed__)) fx_image_s {
+		u16 control; //fcw
+		u16 status; //fsw
+		u16 tag; // ftw
+		u16 opcode; //fop
+		u64 ip; // fpu ip
+		u64 operand;// fpu dp
+		u32 mxcsr;
+		u32 mxcsr_mask;
+
+	} *fx_image;
+
+	fx_save(vcpu->host_fx_image);
+	fpu_init();
+	fx_save(vcpu->guest_fx_image);
+	fx_restore(vcpu->host_fx_image);
+
+	fx_image = (struct fx_image_s *)vcpu->guest_fx_image;
+	fx_image->mxcsr = 0x1f80;
+	memset(vcpu->guest_fx_image + sizeof(struct fx_image_s),
+	       0, FX_IMAGE_SIZE - sizeof(struct fx_image_s));
+}
+EXPORT_SYMBOL_GPL(fx_init);
+
+/*
+ * Creates some virtual cpus.  Good luck creating more than one.
+ */
+static int kvm_dev_ioctl_create_vcpu(struct kvm *kvm, int n)
+{
+	int r;
+	struct kvm_vcpu *vcpu;
+
+	r = -EINVAL;
+	if (n < 0 || n >= KVM_MAX_VCPUS)
+		goto out;
+
+	vcpu = &kvm->vcpus[n];
+
+	mutex_lock(&vcpu->mutex);
+
+	if (vcpu->vmcs) {
+		mutex_unlock(&vcpu->mutex);
+		return -EEXIST;
+	}
+
+	vcpu->host_fx_image = (char*)ALIGN((hva_t)vcpu->fx_buf,
+					   FX_IMAGE_ALIGN);
+	vcpu->guest_fx_image = vcpu->host_fx_image + FX_IMAGE_SIZE;
+
+	vcpu->cpu = -1;  /* First load will set up TR */
+	vcpu->kvm = kvm;
+	r = kvm_arch_ops->vcpu_create(vcpu);
+	if (r < 0)
+		goto out_free_vcpus;
+
+	kvm_arch_ops->vcpu_load(vcpu);
+
+	r = kvm_arch_ops->vcpu_setup(vcpu);
+	if (r >= 0)
+		r = kvm_mmu_init(vcpu);
+
+	vcpu_put(vcpu);
+
+	if (r < 0)
+		goto out_free_vcpus;
+
+	return 0;
+
+out_free_vcpus:
+	kvm_free_vcpu(vcpu);
+	mutex_unlock(&vcpu->mutex);
+out:
+	return r;
+}
+
+/*
+ * Allocate some memory and give it an address in the guest physical address
+ * space.
+ *
+ * Discontiguous memory is allowed, mostly for framebuffers.
+ */
+static int kvm_dev_ioctl_set_memory_region(struct kvm *kvm,
+					   struct kvm_memory_region *mem)
+{
+	int r;
+	gfn_t base_gfn;
+	unsigned long npages;
+	unsigned long i;
+	struct kvm_memory_slot *memslot;
+	struct kvm_memory_slot old, new;
+	int memory_config_version;
+
+	r = -EINVAL;
+	/* General sanity checks */
+	if (mem->memory_size & (PAGE_SIZE - 1))
+		goto out;
+	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
+		goto out;
+	if (mem->slot >= KVM_MEMORY_SLOTS)
+		goto out;
+	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
+		goto out;
+
+	memslot = &kvm->memslots[mem->slot];
+	base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
+	npages = mem->memory_size >> PAGE_SHIFT;
+
+	if (!npages)
+		mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
+
+raced:
+	spin_lock(&kvm->lock);
+
+	memory_config_version = kvm->memory_config_version;
+	new = old = *memslot;
+
+	new.base_gfn = base_gfn;
+	new.npages = npages;
+	new.flags = mem->flags;
+
+	/* Disallow changing a memory slot's size. */
+	r = -EINVAL;
+	if (npages && old.npages && npages != old.npages)
+		goto out_unlock;
+
+	/* Check for overlaps */
+	r = -EEXIST;
+	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
+		struct kvm_memory_slot *s = &kvm->memslots[i];
+
+		if (s == memslot)
+			continue;
+		if (!((base_gfn + npages <= s->base_gfn) ||
+		      (base_gfn >= s->base_gfn + s->npages)))
+			goto out_unlock;
+	}
+	/*
+	 * Do memory allocations outside lock.  memory_config_version will
+	 * detect any races.
+	 */
+	spin_unlock(&kvm->lock);
+
+	/* Deallocate if slot is being removed */
+	if (!npages)
+		new.phys_mem = 0;
+
+	/* Free page dirty bitmap if unneeded */
+	if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
+		new.dirty_bitmap = 0;
+
+	r = -ENOMEM;
+
+	/* Allocate if a slot is being created */
+	if (npages && !new.phys_mem) {
+		new.phys_mem = vmalloc(npages * sizeof(struct page *));
+
+		if (!new.phys_mem)
+			goto out_free;
+
+		memset(new.phys_mem, 0, npages * sizeof(struct page *));
+		for (i = 0; i < npages; ++i) {
+			new.phys_mem[i] = alloc_page(GFP_HIGHUSER
+						     | __GFP_ZERO);
+			if (!new.phys_mem[i])
+				goto out_free;
+		}
+	}
+
+	/* Allocate page dirty bitmap if needed */
+	if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
+		unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;
+
+		new.dirty_bitmap = vmalloc(dirty_bytes);
+		if (!new.dirty_bitmap)
+			goto out_free;
+		memset(new.dirty_bitmap, 0, dirty_bytes);
+	}
+
+	spin_lock(&kvm->lock);
+
+	if (memory_config_version != kvm->memory_config_version) {
+		spin_unlock(&kvm->lock);
+		kvm_free_physmem_slot(&new, &old);
+		goto raced;
+	}
+
+	r = -EAGAIN;
+	if (kvm->busy)
+		goto out_unlock;
+
+	if (mem->slot >= kvm->nmemslots)
+		kvm->nmemslots = mem->slot + 1;
+
+	*memslot = new;
+	++kvm->memory_config_version;
+
+	spin_unlock(&kvm->lock);
+
+	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+		struct kvm_vcpu *vcpu;
+
+		vcpu = vcpu_load(kvm, i);
+		if (!vcpu)
+			continue;
+		kvm_mmu_reset_context(vcpu);
+		vcpu_put(vcpu);
+	}
+
+	kvm_free_physmem_slot(&old, &new);
+	return 0;
+
+out_unlock:
+	spin_unlock(&kvm->lock);
+out_free:
+	kvm_free_physmem_slot(&new, &old);
+out:
+	return r;
+}
+
+/*
+ * Get (and clear) the dirty memory log for a memory slot.
+ */
+static int kvm_dev_ioctl_get_dirty_log(struct kvm *kvm,
+				       struct kvm_dirty_log *log)
+{
+	struct kvm_memory_slot *memslot;
+	int r, i;
+	int n;
+	unsigned long any = 0;
+
+	spin_lock(&kvm->lock);
+
+	/*
+	 * Prevent changes to guest memory configuration even while the lock
+	 * is not taken.
+	 */
+	++kvm->busy;
+	spin_unlock(&kvm->lock);
+	r = -EINVAL;
+	if (log->slot >= KVM_MEMORY_SLOTS)
+		goto out;
+
+	memslot = &kvm->memslots[log->slot];
+	r = -ENOENT;
+	if (!memslot->dirty_bitmap)
+		goto out;
+
+	n = ALIGN(memslot->npages, 8) / 8;
+
+	for (i = 0; !any && i < n; ++i)
+		any = memslot->dirty_bitmap[i];
+
+	r = -EFAULT;
+	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
+		goto out;
+
+
+	if (any) {
+		spin_lock(&kvm->lock);
+		kvm_mmu_slot_remove_write_access(kvm, log->slot);
+		spin_unlock(&kvm->lock);
+		memset(memslot->dirty_bitmap, 0, n);
+		for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+			struct kvm_vcpu *vcpu = vcpu_load(kvm, i);
+
+			if (!vcpu)
+				continue;
+			kvm_arch_ops->tlb_flush(vcpu);
+			vcpu_put(vcpu);
+		}
+	}
+
+	r = 0;
+
+out:
+	spin_lock(&kvm->lock);
+	--kvm->busy;
+	spin_unlock(&kvm->lock);
+	return r;
+}
+
+struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
+{
+	int i;
+
+	for (i = 0; i < kvm->nmemslots; ++i) {
+		struct kvm_memory_slot *memslot = &kvm->memslots[i];
+
+		if (gfn >= memslot->base_gfn
+		    && gfn < memslot->base_gfn + memslot->npages)
+			return memslot;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gfn_to_memslot);
+
+void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
+{
+	int i;
+	struct kvm_memory_slot *memslot = 0;
+	unsigned long rel_gfn;
+
+	for (i = 0; i < kvm->nmemslots; ++i) {
+		memslot = &kvm->memslots[i];
+
+		if (gfn >= memslot->base_gfn
+		    && gfn < memslot->base_gfn + memslot->npages) {
+
+			if (!memslot || !memslot->dirty_bitmap)
+				return;
+
+			rel_gfn = gfn - memslot->base_gfn;
+
+			/* avoid RMW */
+			if (!test_bit(rel_gfn, memslot->dirty_bitmap))
+				set_bit(rel_gfn, memslot->dirty_bitmap);
+			return;
+		}
+	}
+}
+
+static int emulator_read_std(unsigned long addr,
+			     unsigned long *val,
+			     unsigned int bytes,
+			     struct x86_emulate_ctxt *ctxt)
+{
+	struct kvm_vcpu *vcpu = ctxt->vcpu;
+	void *data = val;
+
+	while (bytes) {
+		gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
+		unsigned offset = addr & (PAGE_SIZE-1);
+		unsigned tocopy = min(bytes, (unsigned)PAGE_SIZE - offset);
+		unsigned long pfn;
+		struct kvm_memory_slot *memslot;
+		void *page;
+
+		if (gpa == UNMAPPED_GVA)
+			return X86EMUL_PROPAGATE_FAULT;
+		pfn = gpa >> PAGE_SHIFT;
+		memslot = gfn_to_memslot(vcpu->kvm, pfn);
+		if (!memslot)
+			return X86EMUL_UNHANDLEABLE;
+		page = kmap_atomic(gfn_to_page(memslot, pfn), KM_USER0);
+
+		memcpy(data, page + offset, tocopy);
+
+		kunmap_atomic(page, KM_USER0);
+
+		bytes -= tocopy;
+		data += tocopy;
+		addr += tocopy;
+	}
+
+	return X86EMUL_CONTINUE;
+}
+
+static int emulator_write_std(unsigned long addr,
+			      unsigned long val,
+			      unsigned int bytes,
+			      struct x86_emulate_ctxt *ctxt)
+{
+	printk(KERN_ERR "emulator_write_std: addr %lx n %d\n",
+	       addr, bytes);
+	return X86EMUL_UNHANDLEABLE;
+}
+
+static int emulator_read_emulated(unsigned long addr,
+				  unsigned long *val,
+				  unsigned int bytes,
+				  struct x86_emulate_ctxt *ctxt)
+{
+	struct kvm_vcpu *vcpu = ctxt->vcpu;
+
+	if (vcpu->mmio_read_completed) {
+		memcpy(val, vcpu->mmio_data, bytes);
+		vcpu->mmio_read_completed = 0;
+		return X86EMUL_CONTINUE;
+	} else if (emulator_read_std(addr, val, bytes, ctxt)
+		   == X86EMUL_CONTINUE)
+		return X86EMUL_CONTINUE;
+	else {
+		gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
+		if (gpa == UNMAPPED_GVA)
+			return vcpu_printf(vcpu, "not present\n"), X86EMUL_PROPAGATE_FAULT;
+		vcpu->mmio_needed = 1;
+		vcpu->mmio_phys_addr = gpa;
+		vcpu->mmio_size = bytes;
+		vcpu->mmio_is_write = 0;
+
+		return X86EMUL_UNHANDLEABLE;
+	}
+}
+
+static int emulator_write_emulated(unsigned long addr,
+				   unsigned long val,
+				   unsigned int bytes,
+				   struct x86_emulate_ctxt *ctxt)
+{
+	struct kvm_vcpu *vcpu = ctxt->vcpu;
+	gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
+
+	if (gpa == UNMAPPED_GVA)
+		return X86EMUL_PROPAGATE_FAULT;
+
+	vcpu->mmio_needed = 1;
+	vcpu->mmio_phys_addr = gpa;
+	vcpu->mmio_size = bytes;
+	vcpu->mmio_is_write = 1;
+	memcpy(vcpu->mmio_data, &val, bytes);
+
+	return X86EMUL_CONTINUE;
+}
+
+static int emulator_cmpxchg_emulated(unsigned long addr,
+				     unsigned long old,
+				     unsigned long new,
+				     unsigned int bytes,
+				     struct x86_emulate_ctxt *ctxt)
+{
+	static int reported;
+
+	if (!reported) {
+		reported = 1;
+		printk(KERN_WARNING "kvm: emulating exchange as write\n");
+	}
+	return emulator_write_emulated(addr, new, bytes, ctxt);
+}
+
+static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
+{
+	return kvm_arch_ops->get_segment_base(vcpu, seg);
+}
+
+int emulate_invlpg(struct kvm_vcpu *vcpu, gva_t address)
+{
+	spin_lock(&vcpu->kvm->lock);
+	vcpu->mmu.inval_page(vcpu, address);
+	spin_unlock(&vcpu->kvm->lock);
+	kvm_arch_ops->invlpg(vcpu, address);
+	return X86EMUL_CONTINUE;
+}
+
+int emulate_clts(struct kvm_vcpu *vcpu)
+{
+	unsigned long cr0 = vcpu->cr0;
+
+	cr0 &= ~CR0_TS_MASK;
+	kvm_arch_ops->set_cr0(vcpu, cr0);
+	return X86EMUL_CONTINUE;
+}
+
+int emulator_get_dr(struct x86_emulate_ctxt* ctxt, int dr, unsigned long *dest)
+{
+	struct kvm_vcpu *vcpu = ctxt->vcpu;
+
+	switch (dr) {
+	case 0 ... 3:
+		*dest = kvm_arch_ops->get_dr(vcpu, dr);
+		return X86EMUL_CONTINUE;
+	default:
+		printk(KERN_DEBUG "%s: unexpected dr %u\n",
+		       __FUNCTION__, dr);
+		return X86EMUL_UNHANDLEABLE;
+	}
+}
+
+int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr, unsigned long value)
+{
+	unsigned long mask = (ctxt->mode == X86EMUL_MODE_PROT64) ? ~0ULL : ~0U;
+	int exception;
+
+	kvm_arch_ops->set_dr(ctxt->vcpu, dr, value & mask, &exception);
+	if (exception) {
+		/* FIXME: better handling */
+		return X86EMUL_UNHANDLEABLE;
+	}
+	return X86EMUL_CONTINUE;
+}
+
+static void report_emulation_failure(struct x86_emulate_ctxt *ctxt)
+{
+	static int reported;
+	u8 opcodes[4];
+	unsigned long rip = ctxt->vcpu->rip;
+	unsigned long rip_linear;
+
+	rip_linear = rip + get_segment_base(ctxt->vcpu, VCPU_SREG_CS);
+
+	if (reported)
+		return;
+
+	emulator_read_std(rip_linear, (void *)opcodes, 4, ctxt);
+
+	printk(KERN_ERR "emulation failed but !mmio_needed?"
+	       " rip %lx %02x %02x %02x %02x\n",
+	       rip, opcodes[0], opcodes[1], opcodes[2], opcodes[3]);
+	reported = 1;
+}
+
+struct x86_emulate_ops emulate_ops = {
+	.read_std            = emulator_read_std,
+	.write_std           = emulator_write_std,
+	.read_emulated       = emulator_read_emulated,
+	.write_emulated      = emulator_write_emulated,
+	.cmpxchg_emulated    = emulator_cmpxchg_emulated,
+};
+
+int emulate_instruction(struct kvm_vcpu *vcpu,
+			struct kvm_run *run,
+			unsigned long cr2,
+			u16 error_code)
+{
+	struct x86_emulate_ctxt emulate_ctxt;
+	int r;
+	int cs_db, cs_l;
+
+	kvm_arch_ops->cache_regs(vcpu);
+
+	kvm_arch_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
+
+	emulate_ctxt.vcpu = vcpu;
+	emulate_ctxt.eflags = kvm_arch_ops->get_rflags(vcpu);
+	emulate_ctxt.cr2 = cr2;
+	emulate_ctxt.mode = (emulate_ctxt.eflags & X86_EFLAGS_VM)
+		? X86EMUL_MODE_REAL : cs_l
+		? X86EMUL_MODE_PROT64 :	cs_db
+		? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
+
+	if (emulate_ctxt.mode == X86EMUL_MODE_PROT64) {
+		emulate_ctxt.cs_base = 0;
+		emulate_ctxt.ds_base = 0;
+		emulate_ctxt.es_base = 0;
+		emulate_ctxt.ss_base = 0;
+	} else {
+		emulate_ctxt.cs_base = get_segment_base(vcpu, VCPU_SREG_CS);
+		emulate_ctxt.ds_base = get_segment_base(vcpu, VCPU_SREG_DS);
+		emulate_ctxt.es_base = get_segment_base(vcpu, VCPU_SREG_ES);
+		emulate_ctxt.ss_base = get_segment_base(vcpu, VCPU_SREG_SS);
+	}
+
+	emulate_ctxt.gs_base = get_segment_base(vcpu, VCPU_SREG_GS);
+	emulate_ctxt.fs_base = get_segment_base(vcpu, VCPU_SREG_FS);
+
+	vcpu->mmio_is_write = 0;
+	r = x86_emulate_memop(&emulate_ctxt, &emulate_ops);
+
+	if ((r || vcpu->mmio_is_write) && run) {
+		run->mmio.phys_addr = vcpu->mmio_phys_addr;
+		memcpy(run->mmio.data, vcpu->mmio_data, 8);
+		run->mmio.len = vcpu->mmio_size;
+		run->mmio.is_write = vcpu->mmio_is_write;
+	}
+
+	if (r) {
+		if (!vcpu->mmio_needed) {
+			report_emulation_failure(&emulate_ctxt);
+			return EMULATE_FAIL;
+		}
+		return EMULATE_DO_MMIO;
+	}
+
+	kvm_arch_ops->decache_regs(vcpu);
+	kvm_arch_ops->set_rflags(vcpu, emulate_ctxt.eflags);
+
+	if (vcpu->mmio_is_write)
+		return EMULATE_DO_MMIO;
+
+	return EMULATE_DONE;
+}
+EXPORT_SYMBOL_GPL(emulate_instruction);
+
+static u64 mk_cr_64(u64 curr_cr, u32 new_val)
+{
+	return (curr_cr & ~((1ULL << 32) - 1)) | new_val;
+}
+
+void realmode_lgdt(struct kvm_vcpu *vcpu, u16 limit, unsigned long base)
+{
+	struct descriptor_table dt = { limit, base };
+
+	kvm_arch_ops->set_gdt(vcpu, &dt);
+}
+
+void realmode_lidt(struct kvm_vcpu *vcpu, u16 limit, unsigned long base)
+{
+	struct descriptor_table dt = { limit, base };
+
+	kvm_arch_ops->set_idt(vcpu, &dt);
+}
+
+void realmode_lmsw(struct kvm_vcpu *vcpu, unsigned long msw,
+		   unsigned long *rflags)
+{
+	lmsw(vcpu, msw);
+	*rflags = kvm_arch_ops->get_rflags(vcpu);
+}
+
+unsigned long realmode_get_cr(struct kvm_vcpu *vcpu, int cr)
+{
+	switch (cr) {
+	case 0:
+		return vcpu->cr0;
+	case 2:
+		return vcpu->cr2;
+	case 3:
+		return vcpu->cr3;
+	case 4:
+		return vcpu->cr4;
+	default:
+		vcpu_printf(vcpu, "%s: unexpected cr %u\n", __FUNCTION__, cr);
+		return 0;
+	}
+}
+
+void realmode_set_cr(struct kvm_vcpu *vcpu, int cr, unsigned long val,
+		     unsigned long *rflags)
+{
+	switch (cr) {
+	case 0:
+		set_cr0(vcpu, mk_cr_64(vcpu->cr0, val));
+		*rflags = kvm_arch_ops->get_rflags(vcpu);
+		break;
+	case 2:
+		vcpu->cr2 = val;
+		break;
+	case 3:
+		set_cr3(vcpu, val);
+		break;
+	case 4:
+		set_cr4(vcpu, mk_cr_64(vcpu->cr4, val));
+		break;
+	default:
+		vcpu_printf(vcpu, "%s: unexpected cr %u\n", __FUNCTION__, cr);
+	}
+}
+
+/*
+ * Reads an msr value (of 'msr_index') into 'pdata'.
+ * Returns 0 on success, non-0 otherwise.
+ * Assumes vcpu_load() was already called.
+ */
+static int get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
+{
+	return kvm_arch_ops->get_msr(vcpu, msr_index, pdata);
+}
+
+#ifdef __x86_64__
+
+void set_efer(struct kvm_vcpu *vcpu, u64 efer)
+{
+	struct vmx_msr_entry *msr;
+
+	if (efer & EFER_RESERVED_BITS) {
+		printk(KERN_DEBUG "set_efer: 0x%llx #GP, reserved bits\n",
+		       efer);
+		inject_gp(vcpu);
+		return;
+	}
+
+	if (is_paging(vcpu)
+	    && (vcpu->shadow_efer & EFER_LME) != (efer & EFER_LME)) {
+		printk(KERN_DEBUG "set_efer: #GP, change LME while paging\n");
+		inject_gp(vcpu);
+		return;
+	}
+
+	efer &= ~EFER_LMA;
+	efer |= vcpu->shadow_efer & EFER_LMA;
+
+	vcpu->shadow_efer = efer;
+
+	msr = find_msr_entry(vcpu, MSR_EFER);
+
+	if (!(efer & EFER_LMA))
+	    efer &= ~EFER_LME;
+	msr->data = efer;
+}
+EXPORT_SYMBOL_GPL(set_efer);
+
+#endif
+
+/*
+ * Writes msr value into into the appropriate "register".
+ * Returns 0 on success, non-0 otherwise.
+ * Assumes vcpu_load() was already called.
+ */
+static int set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
+{
+	return kvm_arch_ops->set_msr(vcpu, msr_index, data);
+}
+
+void kvm_resched(struct kvm_vcpu *vcpu)
+{
+	vcpu_put(vcpu);
+	cond_resched();
+	/* Cannot fail -  no vcpu unplug yet. */
+	vcpu_load(vcpu->kvm, vcpu_slot(vcpu));
+}
+EXPORT_SYMBOL_GPL(kvm_resched);
+
+void load_msrs(struct vmx_msr_entry *e, int n)
+{
+	int i;
+
+	for (i = 0; i < n; ++i)
+		wrmsrl(e[i].index, e[i].data);
+}
+EXPORT_SYMBOL_GPL(load_msrs);
+
+void save_msrs(struct vmx_msr_entry *e, int n)
+{
+	int i;
+
+	for (i = 0; i < n; ++i)
+		rdmsrl(e[i].index, e[i].data);
+}
+EXPORT_SYMBOL_GPL(save_msrs);
+
+static int kvm_dev_ioctl_run(struct kvm *kvm, struct kvm_run *kvm_run)
+{
+	struct kvm_vcpu *vcpu;
+	int r;
+
+	if (kvm_run->vcpu < 0 || kvm_run->vcpu >= KVM_MAX_VCPUS)
+		return -EINVAL;
+
+	vcpu = vcpu_load(kvm, kvm_run->vcpu);
+	if (!vcpu)
+		return -ENOENT;
+
+	if (kvm_run->emulated) {
+		kvm_arch_ops->skip_emulated_instruction(vcpu);
+		kvm_run->emulated = 0;
+	}
+
+	if (kvm_run->mmio_completed) {
+		memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
+		vcpu->mmio_read_completed = 1;
+	}
+
+	vcpu->mmio_needed = 0;
+
+	r = kvm_arch_ops->run(vcpu, kvm_run);
+
+	vcpu_put(vcpu);
+	return r;
+}
+
+static int kvm_dev_ioctl_get_regs(struct kvm *kvm, struct kvm_regs *regs)
+{
+	struct kvm_vcpu *vcpu;
+
+	if (regs->vcpu < 0 || regs->vcpu >= KVM_MAX_VCPUS)
+		return -EINVAL;
+
+	vcpu = vcpu_load(kvm, regs->vcpu);
+	if (!vcpu)
+		return -ENOENT;
+
+	kvm_arch_ops->cache_regs(vcpu);
+
+	regs->rax = vcpu->regs[VCPU_REGS_RAX];
+	regs->rbx = vcpu->regs[VCPU_REGS_RBX];
+	regs->rcx = vcpu->regs[VCPU_REGS_RCX];
+	regs->rdx = vcpu->regs[VCPU_REGS_RDX];
+	regs->rsi = vcpu->regs[VCPU_REGS_RSI];
+	regs->rdi = vcpu->regs[VCPU_REGS_RDI];
+	regs->rsp = vcpu->regs[VCPU_REGS_RSP];
+	regs->rbp = vcpu->regs[VCPU_REGS_RBP];
+#ifdef __x86_64__
+	regs->r8 = vcpu->regs[VCPU_REGS_R8];
+	regs->r9 = vcpu->regs[VCPU_REGS_R9];
+	regs->r10 = vcpu->regs[VCPU_REGS_R10];
+	regs->r11 = vcpu->regs[VCPU_REGS_R11];
+	regs->r12 = vcpu->regs[VCPU_REGS_R12];
+	regs->r13 = vcpu->regs[VCPU_REGS_R13];
+	regs->r14 = vcpu->regs[VCPU_REGS_R14];
+	regs->r15 = vcpu->regs[VCPU_REGS_R15];
+#endif
+
+	regs->rip = vcpu->rip;
+	regs->rflags = kvm_arch_ops->get_rflags(vcpu);
+
+	/*
+	 * Don't leak debug flags in case they were set for guest debugging
+	 */
+	if (vcpu->guest_debug.enabled && vcpu->guest_debug.singlestep)
+		regs->rflags &= ~(X86_EFLAGS_TF | X86_EFLAGS_RF);
+
+	vcpu_put(vcpu);
+
+	return 0;
+}
+
+static int kvm_dev_ioctl_set_regs(struct kvm *kvm, struct kvm_regs *regs)
+{
+	struct kvm_vcpu *vcpu;
+
+	if (regs->vcpu < 0 || regs->vcpu >= KVM_MAX_VCPUS)
+		return -EINVAL;
+
+	vcpu = vcpu_load(kvm, regs->vcpu);
+	if (!vcpu)
+		return -ENOENT;
+
+	vcpu->regs[VCPU_REGS_RAX] = regs->rax;
+	vcpu->regs[VCPU_REGS_RBX] = regs->rbx;
+	vcpu->regs[VCPU_REGS_RCX] = regs->rcx;
+	vcpu->regs[VCPU_REGS_RDX] = regs->rdx;
+	vcpu->regs[VCPU_REGS_RSI] = regs->rsi;
+	vcpu->regs[VCPU_REGS_RDI] = regs->rdi;
+	vcpu->regs[VCPU_REGS_RSP] = regs->rsp;
+	vcpu->regs[VCPU_REGS_RBP] = regs->rbp;
+#ifdef __x86_64__
+	vcpu->regs[VCPU_REGS_R8] = regs->r8;
+	vcpu->regs[VCPU_REGS_R9] = regs->r9;
+	vcpu->regs[VCPU_REGS_R10] = regs->r10;
+	vcpu->regs[VCPU_REGS_R11] = regs->r11;
+	vcpu->regs[VCPU_REGS_R12] = regs->r12;
+	vcpu->regs[VCPU_REGS_R13] = regs->r13;
+	vcpu->regs[VCPU_REGS_R14] = regs->r14;
+	vcpu->regs[VCPU_REGS_R15] = regs->r15;
+#endif
+
+	vcpu->rip = regs->rip;
+	kvm_arch_ops->set_rflags(vcpu, regs->rflags);
+
+	kvm_arch_ops->decache_regs(vcpu);
+
+	vcpu_put(vcpu);
+
+	return 0;
+}
+
+static void get_segment(struct kvm_vcpu *vcpu,
+			struct kvm_segment *var, int seg)
+{
+	return kvm_arch_ops->get_segment(vcpu, var, seg);
+}
+
+static int kvm_dev_ioctl_get_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
+{
+	struct kvm_vcpu *vcpu;
+	struct descriptor_table dt;
+
+	if (sregs->vcpu < 0 || sregs->vcpu >= KVM_MAX_VCPUS)
+		return -EINVAL;
+	vcpu = vcpu_load(kvm, sregs->vcpu);
+	if (!vcpu)
+		return -ENOENT;
+
+	get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
+	get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
+	get_segment(vcpu, &sregs->es, VCPU_SREG_ES);
+	get_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
+	get_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
+	get_segment(vcpu, &sregs->ss, VCPU_SREG_SS);
+
+	get_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
+	get_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);
+
+	kvm_arch_ops->get_idt(vcpu, &dt);
+	sregs->idt.limit = dt.limit;
+	sregs->idt.base = dt.base;
+	kvm_arch_ops->get_gdt(vcpu, &dt);
+	sregs->gdt.limit = dt.limit;
+	sregs->gdt.base = dt.base;
+
+	sregs->cr0 = vcpu->cr0;
+	sregs->cr2 = vcpu->cr2;
+	sregs->cr3 = vcpu->cr3;
+	sregs->cr4 = vcpu->cr4;
+	sregs->cr8 = vcpu->cr8;
+	sregs->efer = vcpu->shadow_efer;
+	sregs->apic_base = vcpu->apic_base;
+
+	memcpy(sregs->interrupt_bitmap, vcpu->irq_pending,
+	       sizeof sregs->interrupt_bitmap);
+
+	vcpu_put(vcpu);
+
+	return 0;
+}
+
+static void set_segment(struct kvm_vcpu *vcpu,
+			struct kvm_segment *var, int seg)
+{
+	return kvm_arch_ops->set_segment(vcpu, var, seg);
+}
+
+static int kvm_dev_ioctl_set_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
+{
+	struct kvm_vcpu *vcpu;
+	int mmu_reset_needed = 0;
+	int i;
+	struct descriptor_table dt;
+
+	if (sregs->vcpu < 0 || sregs->vcpu >= KVM_MAX_VCPUS)
+		return -EINVAL;
+	vcpu = vcpu_load(kvm, sregs->vcpu);
+	if (!vcpu)
+		return -ENOENT;
+
+	set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
+	set_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
+	set_segment(vcpu, &sregs->es, VCPU_SREG_ES);
+	set_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
+	set_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
+	set_segment(vcpu, &sregs->ss, VCPU_SREG_SS);
+
+	set_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
+	set_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);
+
+	dt.limit = sregs->idt.limit;
+	dt.base = sregs->idt.base;
+	kvm_arch_ops->set_idt(vcpu, &dt);
+	dt.limit = sregs->gdt.limit;
+	dt.base = sregs->gdt.base;
+	kvm_arch_ops->set_gdt(vcpu, &dt);
+
+	vcpu->cr2 = sregs->cr2;
+	mmu_reset_needed |= vcpu->cr3 != sregs->cr3;
+	vcpu->cr3 = sregs->cr3;
+
+	vcpu->cr8 = sregs->cr8;
+
+	mmu_reset_needed |= vcpu->shadow_efer != sregs->efer;
+#ifdef __x86_64__
+	kvm_arch_ops->set_efer(vcpu, sregs->efer);
+#endif
+	vcpu->apic_base = sregs->apic_base;
+
+	mmu_reset_needed |= vcpu->cr0 != sregs->cr0;
+	kvm_arch_ops->set_cr0_no_modeswitch(vcpu, sregs->cr0);
+
+	mmu_reset_needed |= vcpu->cr4 != sregs->cr4;
+	kvm_arch_ops->set_cr4(vcpu, sregs->cr4);
+
+	if (mmu_reset_needed)
+		kvm_mmu_reset_context(vcpu);
+
+	memcpy(vcpu->irq_pending, sregs->interrupt_bitmap,
+	       sizeof vcpu->irq_pending);
+	vcpu->irq_summary = 0;
+	for (i = 0; i < NR_IRQ_WORDS; ++i)
+		if (vcpu->irq_pending[i])
+			__set_bit(i, &vcpu->irq_summary);
+
+	vcpu_put(vcpu);
+
+	return 0;
+}
+
+/*
+ * List of msr numbers which we expose to userspace through KVM_GET_MSRS
+ * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
+ */
+static u32 msrs_to_save[] = {
+	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
+	MSR_K6_STAR,
+#ifdef __x86_64__
+	MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
+#endif
+	MSR_IA32_TIME_STAMP_COUNTER,
+};
+
+
+/*
+ * Adapt set_msr() to msr_io()'s calling convention
+ */
+static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
+{
+	return set_msr(vcpu, index, *data);
+}
+
+/*
+ * Read or write a bunch of msrs. All parameters are kernel addresses.
+ *
+ * @return number of msrs set successfully.
+ */
+static int __msr_io(struct kvm *kvm, struct kvm_msrs *msrs,
+		    struct kvm_msr_entry *entries,
+		    int (*do_msr)(struct kvm_vcpu *vcpu,
+				  unsigned index, u64 *data))
+{
+	struct kvm_vcpu *vcpu;
+	int i;
+
+	if (msrs->vcpu < 0 || msrs->vcpu >= KVM_MAX_VCPUS)
+		return -EINVAL;
+
+	vcpu = vcpu_load(kvm, msrs->vcpu);
+	if (!vcpu)
+		return -ENOENT;
+
+	for (i = 0; i < msrs->nmsrs; ++i)
+		if (do_msr(vcpu, entries[i].index, &entries[i].data))
+			break;
+
+	vcpu_put(vcpu);
+
+	return i;
+}
+
+/*
+ * Read or write a bunch of msrs. Parameters are user addresses.
+ *
+ * @return number of msrs set successfully.
+ */
+static int msr_io(struct kvm *kvm, struct kvm_msrs __user *user_msrs,
+		  int (*do_msr)(struct kvm_vcpu *vcpu,
+				unsigned index, u64 *data),
+		  int writeback)
+{
+	struct kvm_msrs msrs;
+	struct kvm_msr_entry *entries;
+	int r, n;
+	unsigned size;
+
+	r = -EFAULT;
+	if (copy_from_user(&msrs, user_msrs, sizeof msrs))
+		goto out;
+
+	r = -E2BIG;
+	if (msrs.nmsrs >= MAX_IO_MSRS)
+		goto out;
+
+	r = -ENOMEM;
+	size = sizeof(struct kvm_msr_entry) * msrs.nmsrs;
+	entries = vmalloc(size);
+	if (!entries)
+		goto out;
+
+	r = -EFAULT;
+	if (copy_from_user(entries, user_msrs->entries, size))
+		goto out_free;
+
+	r = n = __msr_io(kvm, &msrs, entries, do_msr);
+	if (r < 0)
+		goto out_free;
+
+	r = -EFAULT;
+	if (writeback && copy_to_user(user_msrs->entries, entries, size))
+		goto out_free;
+
+	r = n;
+
+out_free:
+	vfree(entries);
+out:
+	return r;
+}
+
+/*
+ * Translate a guest virtual address to a guest physical address.
+ */
+static int kvm_dev_ioctl_translate(struct kvm *kvm, struct kvm_translation *tr)
+{
+	unsigned long vaddr = tr->linear_address;
+	struct kvm_vcpu *vcpu;
+	gpa_t gpa;
+
+	vcpu = vcpu_load(kvm, tr->vcpu);
+	if (!vcpu)
+		return -ENOENT;
+	spin_lock(&kvm->lock);
+	gpa = vcpu->mmu.gva_to_gpa(vcpu, vaddr);
+	tr->physical_address = gpa;
+	tr->valid = gpa != UNMAPPED_GVA;
+	tr->writeable = 1;
+	tr->usermode = 0;
+	spin_unlock(&kvm->lock);
+	vcpu_put(vcpu);
+
+	return 0;
+}
+
+static int kvm_dev_ioctl_interrupt(struct kvm *kvm, struct kvm_interrupt *irq)
+{
+	struct kvm_vcpu *vcpu;
+
+	if (irq->vcpu < 0 || irq->vcpu >= KVM_MAX_VCPUS)
+		return -EINVAL;
+	if (irq->irq < 0 || irq->irq >= 256)
+		return -EINVAL;
+	vcpu = vcpu_load(kvm, irq->vcpu);
+	if (!vcpu)
+		return -ENOENT;
+
+	set_bit(irq->irq, vcpu->irq_pending);
+	set_bit(irq->irq / BITS_PER_LONG, &vcpu->irq_summary);
+
+	vcpu_put(vcpu);
+
+	return 0;
+}
+
+static int kvm_dev_ioctl_debug_guest(struct kvm *kvm,
+				     struct kvm_debug_guest *dbg)
+{
+	struct kvm_vcpu *vcpu;
+	int r;
+
+	if (dbg->vcpu < 0 || dbg->vcpu >= KVM_MAX_VCPUS)
+		return -EINVAL;
+	vcpu = vcpu_load(kvm, dbg->vcpu);
+	if (!vcpu)
+		return -ENOENT;
+
+	r = kvm_arch_ops->set_guest_debug(vcpu, dbg);
+
+	vcpu_put(vcpu);
+
+	return r;
+}
+
+static long kvm_dev_ioctl(struct file *filp,
+			  unsigned int ioctl, unsigned long arg)
+{
+	struct kvm *kvm = filp->private_data;
+	int r = -EINVAL;
+
+	switch (ioctl) {
+	case KVM_CREATE_VCPU: {
+		r = kvm_dev_ioctl_create_vcpu(kvm, arg);
+		if (r)
+			goto out;
+		break;
+	}
+	case KVM_RUN: {
+		struct kvm_run kvm_run;
+
+		r = -EFAULT;
+		if (copy_from_user(&kvm_run, (void *)arg, sizeof kvm_run))
+			goto out;
+		r = kvm_dev_ioctl_run(kvm, &kvm_run);
+		if (r < 0)
+			goto out;
+		r = -EFAULT;
+		if (copy_to_user((void *)arg, &kvm_run, sizeof kvm_run))
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_GET_REGS: {
+		struct kvm_regs kvm_regs;
+
+		r = -EFAULT;
+		if (copy_from_user(&kvm_regs, (void *)arg, sizeof kvm_regs))
+			goto out;
+		r = kvm_dev_ioctl_get_regs(kvm, &kvm_regs);
+		if (r)
+			goto out;
+		r = -EFAULT;
+		if (copy_to_user((void *)arg, &kvm_regs, sizeof kvm_regs))
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_SET_REGS: {
+		struct kvm_regs kvm_regs;
+
+		r = -EFAULT;
+		if (copy_from_user(&kvm_regs, (void *)arg, sizeof kvm_regs))
+			goto out;
+		r = kvm_dev_ioctl_set_regs(kvm, &kvm_regs);
+		if (r)
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_GET_SREGS: {
+		struct kvm_sregs kvm_sregs;
+
+		r = -EFAULT;
+		if (copy_from_user(&kvm_sregs, (void *)arg, sizeof kvm_sregs))
+			goto out;
+		r = kvm_dev_ioctl_get_sregs(kvm, &kvm_sregs);
+		if (r)
+			goto out;
+		r = -EFAULT;
+		if (copy_to_user((void *)arg, &kvm_sregs, sizeof kvm_sregs))
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_SET_SREGS: {
+		struct kvm_sregs kvm_sregs;
+
+		r = -EFAULT;
+		if (copy_from_user(&kvm_sregs, (void *)arg, sizeof kvm_sregs))
+			goto out;
+		r = kvm_dev_ioctl_set_sregs(kvm, &kvm_sregs);
+		if (r)
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_TRANSLATE: {
+		struct kvm_translation tr;
+
+		r = -EFAULT;
+		if (copy_from_user(&tr, (void *)arg, sizeof tr))
+			goto out;
+		r = kvm_dev_ioctl_translate(kvm, &tr);
+		if (r)
+			goto out;
+		r = -EFAULT;
+		if (copy_to_user((void *)arg, &tr, sizeof tr))
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_INTERRUPT: {
+		struct kvm_interrupt irq;
+
+		r = -EFAULT;
+		if (copy_from_user(&irq, (void *)arg, sizeof irq))
+			goto out;
+		r = kvm_dev_ioctl_interrupt(kvm, &irq);
+		if (r)
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_DEBUG_GUEST: {
+		struct kvm_debug_guest dbg;
+
+		r = -EFAULT;
+		if (copy_from_user(&dbg, (void *)arg, sizeof dbg))
+			goto out;
+		r = kvm_dev_ioctl_debug_guest(kvm, &dbg);
+		if (r)
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_SET_MEMORY_REGION: {
+		struct kvm_memory_region kvm_mem;
+
+		r = -EFAULT;
+		if (copy_from_user(&kvm_mem, (void *)arg, sizeof kvm_mem))
+			goto out;
+		r = kvm_dev_ioctl_set_memory_region(kvm, &kvm_mem);
+		if (r)
+			goto out;
+		break;
+	}
+	case KVM_GET_DIRTY_LOG: {
+		struct kvm_dirty_log log;
+
+		r = -EFAULT;
+		if (copy_from_user(&log, (void *)arg, sizeof log))
+			goto out;
+		r = kvm_dev_ioctl_get_dirty_log(kvm, &log);
+		if (r)
+			goto out;
+		break;
+	}
+	case KVM_GET_MSRS:
+		r = msr_io(kvm, (void __user *)arg, get_msr, 1);
+		break;
+	case KVM_SET_MSRS:
+		r = msr_io(kvm, (void __user *)arg, do_set_msr, 0);
+		break;
+	case KVM_GET_MSR_INDEX_LIST: {
+		struct kvm_msr_list __user *user_msr_list = (void __user *)arg;
+		struct kvm_msr_list msr_list;
+		unsigned n;
+
+		r = -EFAULT;
+		if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list))
+			goto out;
+		n = msr_list.nmsrs;
+		msr_list.nmsrs = ARRAY_SIZE(msrs_to_save);
+		if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list))
+			goto out;
+		r = -E2BIG;
+		if (n < ARRAY_SIZE(msrs_to_save))
+			goto out;
+		r = -EFAULT;
+		if (copy_to_user(user_msr_list->indices, &msrs_to_save,
+				 sizeof msrs_to_save))
+			goto out;
+		r = 0;
+	}
+	default:
+		;
+	}
+out:
+	return r;
+}
+
+static struct page *kvm_dev_nopage(struct vm_area_struct *vma,
+				   unsigned long address,
+				   int *type)
+{
+	struct kvm *kvm = vma->vm_file->private_data;
+	unsigned long pgoff;
+	struct kvm_memory_slot *slot;
+	struct page *page;
+
+	*type = VM_FAULT_MINOR;
+	pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+	slot = gfn_to_memslot(kvm, pgoff);
+	if (!slot)
+		return NOPAGE_SIGBUS;
+	page = gfn_to_page(slot, pgoff);
+	if (!page)
+		return NOPAGE_SIGBUS;
+	get_page(page);
+	return page;
+}
+
+static struct vm_operations_struct kvm_dev_vm_ops = {
+	.nopage = kvm_dev_nopage,
+};
+
+static int kvm_dev_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	vma->vm_ops = &kvm_dev_vm_ops;
+	return 0;
+}
+
+static struct file_operations kvm_chardev_ops = {
+	.open		= kvm_dev_open,
+	.release        = kvm_dev_release,
+	.unlocked_ioctl = kvm_dev_ioctl,
+	.compat_ioctl   = kvm_dev_ioctl,
+	.mmap           = kvm_dev_mmap,
+};
+
+static struct miscdevice kvm_dev = {
+	MISC_DYNAMIC_MINOR,
+	"kvm",
+	&kvm_chardev_ops,
+};
+
+static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
+                       void *v)
+{
+	if (val == SYS_RESTART) {
+		/*
+		 * Some (well, at least mine) BIOSes hang on reboot if
+		 * in vmx root mode.
+		 */
+		printk(KERN_INFO "kvm: exiting hardware virtualization\n");
+		on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block kvm_reboot_notifier = {
+	.notifier_call = kvm_reboot,
+	.priority = 0,
+};
+
+static __init void kvm_init_debug(void)
+{
+	struct kvm_stats_debugfs_item *p;
+
+	debugfs_dir = debugfs_create_dir("kvm", 0);
+	for (p = debugfs_entries; p->name; ++p)
+		p->dentry = debugfs_create_u32(p->name, 0444, debugfs_dir,
+					       p->data);
+}
+
+static void kvm_exit_debug(void)
+{
+	struct kvm_stats_debugfs_item *p;
+
+	for (p = debugfs_entries; p->name; ++p)
+		debugfs_remove(p->dentry);
+	debugfs_remove(debugfs_dir);
+}
+
+hpa_t bad_page_address;
+
+int kvm_init_arch(struct kvm_arch_ops *ops, struct module *module)
+{
+	int r;
+
+	kvm_arch_ops = ops;
+
+	if (!kvm_arch_ops->cpu_has_kvm_support()) {
+		printk(KERN_ERR "kvm: no hardware support\n");
+		return -EOPNOTSUPP;
+	}
+	if (kvm_arch_ops->disabled_by_bios()) {
+		printk(KERN_ERR "kvm: disabled by bios\n");
+		return -EOPNOTSUPP;
+	}
+
+	r = kvm_arch_ops->hardware_setup();
+	if (r < 0)
+	    return r;
+
+	on_each_cpu(kvm_arch_ops->hardware_enable, 0, 0, 1);
+	register_reboot_notifier(&kvm_reboot_notifier);
+
+	kvm_chardev_ops.owner = module;
+
+	r = misc_register(&kvm_dev);
+	if (r) {
+		printk (KERN_ERR "kvm: misc device register failed\n");
+		goto out_free;
+	}
+
+	return r;
+
+out_free:
+	unregister_reboot_notifier(&kvm_reboot_notifier);
+	on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
+	kvm_arch_ops->hardware_unsetup();
+	return r;
+}
+
+void kvm_exit_arch(void)
+{
+	misc_deregister(&kvm_dev);
+
+	unregister_reboot_notifier(&kvm_reboot_notifier);
+	on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
+	kvm_arch_ops->hardware_unsetup();
+}
+
+static __init int kvm_init(void)
+{
+	static struct page *bad_page;
+	int r = 0;
+
+	kvm_init_debug();
+
+	if ((bad_page = alloc_page(GFP_KERNEL)) == NULL) {
+		r = -ENOMEM;
+		goto out;
+	}
+
+	bad_page_address = page_to_pfn(bad_page) << PAGE_SHIFT;
+	memset(__va(bad_page_address), 0, PAGE_SIZE);
+
+	return r;
+
+out:
+	kvm_exit_debug();
+	return r;
+}
+
+static __exit void kvm_exit(void)
+{
+	kvm_exit_debug();
+	__free_page(pfn_to_page(bad_page_address >> PAGE_SHIFT));
+}
+
+module_init(kvm_init)
+module_exit(kvm_exit)
+
+EXPORT_SYMBOL_GPL(kvm_init_arch);
+EXPORT_SYMBOL_GPL(kvm_exit_arch);